JP2604247B2 - Cooling device defrost control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a defrost control device for a cooling device having a plurality of refrigeration units.

2. Description of the Related Art Japanese Patent Laid-Open No. 63-207955 discloses a defrosting control device for a cooling device having two refrigeration cycles. On the other hand, the defrost means is turned on after a predetermined time has elapsed, and
Refrigerator equipped with defrost control means to turn off
There is JP-A-2-210382.

In the above-described technology, a controller that controls the operation of the compressor is configured to alternately perform a defrosting operation of two refrigeration cycles.

On the other hand, in the above technology, a refrigerant circuit including a compressor, a radiator, a cooler, a flow path opening means interposed between the radiator and the cooler, and a defroster for a cooler having a heater Means, a flow path opening / closing control means for closing the flow path opening / closing means after a lapse of a predetermined time from the end of defrosting of the defrosting means, and opening the flow path opening / closing means at the end of the defrosting; There is disclosed a device provided with a defrost control means for turning on the means and turning off at the end of defrosting.

Problems to be Solved by the Invention In the above conventional technology, since the defrosting of the refrigeration unit is performed alternately, the defrosting time in the refrigeration unit during the defrosting operation due to the influence of the cool air due to the cooling operation. There has been a problem that the cooling efficiency of the refrigeration unit during the cooling operation is reduced due to the effect of warm air trapped in the refrigeration unit due to the defrosting operation. In addition, since only one of the two systems performs the cooling operation, it is undeniable that the cooling capacity is significantly reduced as compared with the simultaneous cooling operation of the two systems.

On the other hand, when a large storage is configured by simply mounting a plurality of refrigeration units in the above-described technology, the defrosting operation in each refrigeration unit is simply performed independently, and the cooling capacity of each refrigeration unit has In addition to not being able to fully exert the defrosting operation, the defrosting operation is started independently for each unit, so that the defrosting time is extended as described above or the defrosting is performed in a state where the frost remains in the cooler. The frost sometimes ended.

Further, as disclosed in Japanese Patent Application Laid-Open No. 63-96468, there is a method in which defrosting operations in a plurality of refrigerating units are forcibly synchronized with each other. If only the frost operation is forcibly synchronized and there are two timed devices having different periods to determine the defrost start time, the defrosting operation is performed regardless of which of the timed devices having different periods is selected. There was no idea that the operation would be forcibly synchronized.

Therefore, in the present invention, the defrosting operation in the plurality of refrigeration units is forcibly synchronized, and even when there are two timed devices having different periods for determining the defrost start time, the cycle is not changed. It is an object of the present invention to provide a defrosting control device for a cooling device capable of forcibly synchronizing the defrosting operation regardless of which one of the different timed devices is selected.

Means for Solving the Problems The present invention relates to a cooling apparatus including a plurality of refrigeration units each having a cooling unit including a compressor, a condenser, a defrosting unit, and the like. A controller for controlling the operation of the cooling unit, and a first controller provided in the controller for controlling the start of defrosting of the defrosting means.
And the refrigeration unit is separate and connected in parallel to each of the first timed devices, and controls the start of defrosting at a different cycle from the first timed device to set a second time period. A time limiter, a selection means for selecting either the first or second time limiter, and a defrost start time limit for each refrigeration unit regardless of which of the first or second time limiter is selected by the selection means. And a synchronizing circuit for synchronizing.

The second time limiter includes a first timer provided in each refrigeration unit.
Because each of the timed devices is connected in parallel, the second timed device acts to connect the first timed devices in parallel, and as a result, the start of the defrosting operation of each unit It is determined by either the first or the second timed device. In addition, since the selection means is provided, the defrosting operation start time by one of the first and second timed devices is selected, and the defrosting is performed by a cycle setting according to a request such as a season or a purpose of use. The operation can be started. Further, a synchronization circuit for synchronizing the defrosting start timing of each refrigeration unit is provided irrespective of which one of the first and second time limiters is selected by the selection means. Thus, all the refrigeration units start the defrosting operation at the same time.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

1 is a prefabricated refrigerator-freezer, and 2 is a cooling device, which is a compressor 3, a condenser 4, an evaporator 5, a blower for a condenser 6, a blower for an evaporator 7, a defrosting means 8, and a defrosting end detecting means ( Refrigeration unit 10 including a cooling unit R including a controller 9 and the like.
In this example, three refrigeration units are used, and since the internal configuration of each unit is the same, the description and reference numerals for one of them will be used instead of the other units. In order to distinguish the refrigeration unit from the refrigeration unit, only 10
A (representative), 10B, and 10C.

The cooling device 2 performs temperature control so as to maintain the inside of the refrigerator 1 at a set temperature while alternately performing a cooling operation and a defrosting operation. The operation is controlled by a controller 9 described later. I have. This controller 9
Is configured to alternately perform the cooling operation and the defrosting operation. Here, only the defrosting control device S that performs the defrosting control of the cooling unit R will be described.

FIG. 1 is a schematic circuit diagram of a defrosting control device S for a cooling device, in which each refrigeration unit 10 and a power source (here, an AC power source) are connected.
20, a second time limiter 40 and each refrigeration unit R
Are connected in parallel.

Each refrigeration unit 10 includes a cooling unit R, a controller 9, and a synchronization circuit 50.

The controller 9 includes a central processing unit 41, a RAM (random access memory) 42 for providing data to the central processing unit 41, and a first time limit device 43 for causing the cooling unit R to periodically perform defrosting. It has.

The first time limiter 43 starts the time counting operation from the end of the defrosting operation [after using the hot gas as the defrosting means, after the hot gas recovery operation after the end of the defrosting operation, and when turning on the power when turning on the power]. After the start, an operation is performed to output a signal (for example, a count end signal) to the central processing unit 41 after a lapse of a predetermined time. The first time limiter 43 can set the cycle in a relatively short time range from a predetermined range, for example, about 1 hour to 15 hours.

The synchronization circuit 50 is connected to a transistor 51 whose base is connected to the output terminal of the controller 9, a relay coil 52 connected between the collector of the transistor 51 and a DC power supply (not shown), and to the AC power supply 20. And a phototransistor 55 that conducts when the light-emitting diode 54 emits light. The collector of the phototransistor 55 is connected to a DC power supply via a resistor 56, Is connected to the input terminal of The light emitting diode 54 and the phototransistor 55 are so-called photocouplers P. Then, in each synchronization circuit 50, the relay contacts 53 are connected to the connection line 30A.
Are connected in parallel with each other, and the light emitting diode 54
Are connected in parallel with each other by connection line 30B, and relay contact 5
The connection points between 3 and the light emitting diode 54 are connected in parallel with each other by a connection line 30C. That is, connection line 30 (30A-30C)
Connect the respective synchronous circuits 50 in parallel, and also connect the respective refrigeration units R in parallel.

The second time limit device 40 is connected to both ends of the relay contact 52, and causes the cooling unit R to periodically perform defrosting at a different cycle from the first time limit device 43. Then, the first time limiter 43 for a certain range, for example, about one day to one week.
The period setting can be performed in a relatively long range as compared to the first time limiter 43. Unlike the first time limiter 43, the timer operation is started from the time when the power is turned on, and the contact is opened after a certain period of time set in the period. It operates to close and open after a predetermined time has elapsed. This opening and closing operation is performed at set intervals. However, in this embodiment, the second time limiter 40
Are connected, but a plurality of them may be connected.

60, as shown in FIG. 2, the first timing device 43 and the second
This is a selecting means for selecting either one of the time-limit devices 40.

Based on the above configuration, the operation of the cooling device 2 will be described. However, the refrigerating refrigerator 1 appropriately stores the stored items, and selects the first time limiter 43 (the setting cycle is set to, for example, 8 hours, and see YES in step S1 in FIG. 3) by the selection means. The description will be replaced with the refrigeration unit 10A.

First, by turning on an operation start switch (not shown), a cooling command is output from the controller 9 to start the cooling operation of the cooling unit R. By this cooling operation, the inside of the prefabricated refrigerator-freezer 1 is cooled to lower the temperature in the refrigerator and maintain the set temperature.

Then, after the cooling operation is started (when the power is turned on, from the time of turning on the power), the first timer device 43 has started the time counting operation, and when a set predetermined time (8 hours) elapses, The timer unit 43 outputs a count end signal to the central processing unit 41 (see YES in step S2 in FIG. 3), and the central processing unit 41 outputs a defrosting synchronization command to the synchronization circuit 50 (step S4 in FIG. 3). ), And outputs a count clear command for the first timed device 43 (see step S5 in FIG. 3). Thereafter, a defrosting start command is output to the cooling unit R (see step S6 in FIG. 3), and based on this command, the cooling unit R stops the cooling operation (specifically, stops the compressor 3), The frost operation (specifically, the operation of the defrosting means 8) is started.

On the other hand, according to the synchronization command, the synchronization circuit 50
Is turned on, the relay coil 52 is energized, the relay contact 53 is closed, the light emitting diode 54 emits light, the phototransistor 55 is turned on, and an L level signal is input to the input terminal of the controller 9 (this is a so-called defrost synchronization input). Is entered. When the relay contact 53 is closed, the connection line 30C
After that, the photocoupler P of the synchronous circuit in the other refrigeration units 10B and 10C is also energized, and the other controller receives the same defrosting synchronization input, and the other cooling unit R also performs the cooling operation. Stop and start the defrosting movement in synchronization with the previous cooling unit.

And defrosting movement is continued and defrosting is performed well,
When the completion of the defrosting is detected by the defrosting completion detecting means provided in each refrigeration unit 10, each cooling unit independently ends the defrosting operation and returns to the cooling operation independently.
The first time limiter 43 provided in each of the refrigeration units 10 starts the timing operation again from the time when the defrosting is completed. The count end command of the time limit device of the refrigeration unit that has finished the frost determines the next defrost start time.

Hereinafter, the above-described operation is repeated to maintain the temperature inside the refrigerator 1 at the set temperature.

On the other hand, if the second time limiter 40 is selected by the selecting means 60 (see step S7 in FIG. 3), the second time limiter 40 is selected.
As in the case of the first timer device 43, the time counting operation starts from the time of turning on the power, and when a set time has elapsed, the contact is closed and the above-mentioned relay contact 53 is connected to all the synchronous circuits 50. It operates in the same manner as when it is closed, and each photocoupler P sends an L level signal to the controller 9 (this is a defrosting synchronization input; see step S3 in FIG. 3)
Is input, each controller 9 outputs a defrosting synchronization command to the cooling unit R (step S4), and outputs a count clear command of the first timer device 43 (step S5). A defrosting start command is output to R (step S6), and based on this command, all the cooling units R simultaneously stop the cooling operation (specifically, stop with the cooler 3) and perform the defrosting operation (specifically, the defrosting means). 8) at the same time.

And defrosting operation is continued and defrosting is performed well,
When the end of defrosting is detected by the defrosting end detecting means provided in each refrigeration unit 10, each cooling unit R ends the defrosting operation independently and returns to the cooling operation independently.
Note that the first time limiter 43 provided in each refrigeration unit 10 starts the time counting operation again from the time when the defrosting is completed. However, the selection end means 60 selects the selection means 60 so that the count end signal does not function inside the controller 9. Has become.

According to the above-described configuration, the second timed device 40 is connected in parallel with each of the first timed devices 43 provided in the refrigeration unit 10 in a circuit manner. The timer device 40 acts to connect the first timer devices 43 in parallel, so that the start of the defrosting operation of each cooling unit R is determined by the first or second timer device 43,40. And the controller 9 in each refrigeration unit 10
The cycle of the defrosting time can be changed over a wide range without increasing the capacity of the (central processing unit 41 in the controller 9). Further, since the selection means 60 is provided, the defrosting operation start time by one of the first and second time limit devices 43 and 40 is selected, and the cycle setting according to the request such as the season or the purpose of use is performed. , The defrosting operation can be started.

Further, since the synchronization circuit 60 is provided, the defrosting synchronization input based on the end of counting of one timed device,
All the refrigeration units start the defrosting operation at the same time, and the defrosting time in the refrigeration unit during the defrosting operation is extended due to the influence of the cool air due to the cooling operation as in the related art, or conversely, the refrigeration is performed by the defrosting operation. Due to the warm air in the unit,
The disadvantage that the cooling effect of the refrigeration unit during the cooling operation is reduced can be solved. In particular, the first time limiter itself is pre-installed in each refrigeration unit 10, and the second time limiter is connected to a commercially available timer.
Reference numeral 50 functions as an interface for connecting the timing devices 43 and 40.

[Effects of the Invention] As described above in detail, according to the present invention, the first time limiter for controlling the start of defrosting of the cooling unit in each refrigeration unit and the refrigeration unit are provided separately and the defrosting start is performed. The second timed device to be controlled has different surroundings and is connected in parallel to each refrigeration unit in a circuit manner. Therefore, the defrosting time can be reduced without increasing the capacity of the controller in the refrigeration unit. The cycle can be changed over a wide range, and the cycle setting according to the demands such as the season and the purpose of use can be easily made by selecting the first timed device and the second timed device by the selection means. is there. In addition, when the defrosting operations in the plurality of refrigeration units are forcibly synchronized with each other, even when there are two time limiters having different periods for determining the defrost start time, one of these time limiters is selected. By means of the means, the defrosting operation of each refrigeration unit can be started simultaneously with the cycle setting determined by the first or second time limiter.

[Brief description of the drawings]

Each figure shows an embodiment of the present invention, FIGS. 1 and 2 are schematic circuit diagrams and block circuit diagrams of a defrost control device of a cooling device, respectively. FIG. FIG. 4 is a sectional view showing a state in which the cooling device is installed in the refrigerator. DESCRIPTION OF SYMBOLS 1 ... Prefabricated freezer refrigerator, 2 ... Cooling device, S ... Defrost control device, R ... Cooling unit, 8 ... Defrosting means, 9
…… Controller, 10, 10A ~ 10B …… Refrigeration unit, 40
... Second time limiter, 43 first time limiter, 50 synchronization circuit, 60 selection means.

Claims (1)

(57) [Claims] 1. A cooling device comprising a plurality of refrigeration units each having a cooling unit comprising a compressor, a condenser, a defrosting means, etc., a controller provided for each refrigeration unit and controlling the operation of the cooling unit; A first controller provided in the controller for controlling the start of defrosting of the defrosting means;
And the refrigeration unit is separate and connected in parallel to each of the first timed devices, and controls the start of defrosting at a different cycle from the first timed device to set a second time period. A time limiter, a selection means for selecting either the first or second time limiter, and a defrost start time limit for each refrigeration unit regardless of which of the first or second time limiter is selected by the selection means. A defrosting control device for a cooling device, comprising: